21 research outputs found
Securing Distributed Systems: A Survey on Access Control Techniques for Cloud, Blockchain, IoT and SDN
Access Control is a crucial defense mechanism organizations can deploy to meet modern cybersecurity needs and legal compliance with data privacy. The aim is to prevent unauthorized users and systems from accessing protected resources in a way that exceeds their permissions. The present survey aims to summarize state-of-the-art Access Control techniques, presenting recent research trends in this area. Moreover, as the cyber-attack landscape and zero-trust networking challenges require organizations to consider their Information Security management strategies carefully, in this study, we present a review of contemporary Access Control techniques and technologies being discussed in the literature and the various innovations and evolution of the technology. We also discuss adopting and applying different Access Control techniques and technologies in four upcoming and crucial domains: Cloud Computing, Blockchain, the Internet of Things, and Software-Defined Networking. Finally, we discuss the business adoption strategies for Access Control and how the technology can be integrated into a cybersecurity and network architecture strategy
Obstructions in Security-Aware Business Processes
This Open Access book explores the dilemma-like stalemate between security and regulatory compliance in business processes on the one hand and business continuity and governance on the other. The growing number of regulations, e.g., on information security, data protection, or privacy, implemented in increasingly digitized businesses can have an obstructive effect on the automated execution of business processes. Such security-related obstructions can particularly occur when an access control-based implementation of regulations blocks the execution of business processes. By handling obstructions, security in business processes is supposed to be improved. For this, the book presents a framework that allows the comprehensive analysis, detection, and handling of obstructions in a security-sensitive way. Thereby, methods based on common organizational security policies, process models, and logs are proposed. The Petri net-based modeling and related semantic and language-based research, as well as the analysis of event data and machine learning methods finally lead to the development of algorithms and experiments that can detect and resolve obstructions and are reproducible with the provided software
Towards Better Understanding of User Authorization Query Problem via Multi-variable Complexity Analysis
User authorization queries in the context of role-based access control have
attracted considerable interest in the last 15 years. Such queries are used to
determine whether it is possible to allocate a set of roles to a user that
enables the user to complete a task, in the sense that all the permissions
required to complete the task are assigned to the roles in that set. Answering
such a query, in general, must take into account a number of factors,
including, but not limited to, the roles to which the user is assigned and
constraints on the sets of roles that can be activated. Answering such a query
is known to be NP-hard. The presence of multiple parameters and the need to
find efficient and exact solutions to the problem suggest that a multi-variate
approach will enable us to better understand the complexity of the user
authorization query problem (UAQ). In this paper, we establish a number of
complexity results for UAQ. Specifically, we show the problem remains hard even
when quite restrictive conditions are imposed on the structure of the problem.
Our FPT results show that we have to use either a parameter with potentially
quite large values or quite a restricted version of UAQ. Moreover, our second
FPT algorithm is complex and requires sophisticated, state-of-the-art
techniques. In short, our results show that it is unlikely that all variants of
UAQ that arise in practice can be solved reasonably quickly in general.Comment: Accepted for publication in ACM Transactions on Privacy and Security
(TOPS
An Accurate and Scalable Role Mining Algorithm based on Graph Embedding and Unsupervised Feature Learning
Role-based access control (RBAC) is one of the most widely authorization models used by organizations. In RBAC, accesses are controlled based on the roles of users within the organization. The flexibility and usability of RBAC have encouraged organizations to migrate from traditional discretionary access control (DAC) models to RBAC. The most challenging step in this migration is role mining, which is the process of extracting meaningful roles from existing access control lists. Although various approaches have been proposed to address this NP-complete role mining problem in the literature, they either suffer from low scalability or present heuristics that suffer from low accuracy. In this paper, we propose an accurate and scalable approach to the role mining problem. To this aim, we represent user-permission assignments as a bipartite graph where nodes are users and permissions, and edges are user-permission assignments. Next, we introduce an efficient deep learning algorithm based on random walk sampling to learn low-dimensional representations of the graph, such that permissions that are assigned to similar users are closer in this new space. Then, we use k-means and GMM clustering techniques to cluster permission nodes into roles. We show the effectiveness of our proposed approach by testing it on different datasets. Experimental results show that our approach performs accurate role mining, even for large datasets
Internet of Things in Emergency Medical Care and Services
Emergency care is a critical area of medicine whose outcomes are influenced by the time, availability, and accuracy of contextual information. In addition, the success of emergency care depends on the quality and accuracy of the information received during the emergency call and data collected during the emergency transportation. The success of a follow medical treatment at an emergency care unit depends too on data collected during the two phases: emergency call and transport. However, most information received during an emergency-call is inaccurate and the process of information collection, storage, processing, and retrieval, during an emergency-transportation, is remaining manual and time-consuming. Emergency doctors mostly lack patient’s health records and base the medical treatment on a set of collected information including information provided by the patient or his relatives. Hence, the emergency care delivery is more patient-centered than patient-centric information. Wireless body area network and Internet of Technology (IoT) enable accurate collection of data and are increasingly used in medical applications. This chapter discusses the challenges facing the emergency medical care services delivery, especially in the developing countries. It presents and discusses an IoT platform for a patient-centric-information-based emergency care services delivery. The study is focused on a case of road traffic injury. Results of conducted experiments are discussed
Expressive policy based authorization model for resource-constrained device sensors.
Los capítulos II, III y IV están sujetos a confidencialidad por el autor
92 p.Upcoming smart scenarios enabled by the Internet of Things (IoT) envision smart objects that expose services that can adapt to user behavior or be managed with the goal of achieving higher productivity, often in multistakeholder applications. In such environments, smart things are cheap sensors (and actuators) and, therefore, constrained devices. However, they are also critical components because of the importance of the provided information. Given that, strong security in general and access control in particular is a must.However, tightness, feasibility and usability of existing access control models do not cope well with the principle of least privilege; they lack both expressiveness and the ability to update the policy to be enforced in the sensors. In fact, (1) traditional access control solutions are not feasible in all constrained devices due their big impact on the performance although they provide the highest effectiveness by means of tightness and flexibility. (2) Recent access control solutions designed for constrained devices can be implemented only in not so constrained ones and lack policy expressiveness in the local authorization enforcement. (3) Access control solutions currently feasible in the most severely constrained devices have been based on authentication and very coarse grained and static policies, scale badly, and lack a feasible policy based access control solution aware of local context of sensors.Therefore, there is a need for a suitable End-to-End (E2E) access control model to provide fine grained authorization services in service oriented open scenarios, where operation and management access is by nature dynamic and that integrate massively deployed constrained but manageable sensors. Precisely, the main contribution of this thesis is the specification of such a highly expressive E2E access control model suitable for all sensors including the most severely constrained ones. Concretely, the proposed E2E access control model consists of three main foundations. (1) A hybrid architecture, which combines advantages of both centralized and distributed architectures to enable multi-step authorization. Fine granularity of the enforcement is enabled by (2) an efficient policy language and codification, which are specifically defined to gain expressiveness in the authorization policies and to ensure viability in very-constrained devices. The policy language definition enables both to make granting decisions based on local context conditions, and to react accordingly to the requests by the execution of additional tasks defined as obligations.The policy evaluation and enforcement is performed not only during the security association establishment but also afterward, while such security association is in use. Moreover, this novel model provides also control over access behavior, since iterative re-evaluation of the policy is enabled during each individual resource access.Finally, (3) the establishment of an E2E security association between two mutually authenticated peers through a security protocol named Hidra. Such Hidra protocol, based on symmetric key cryptography, relies on the hybrid three-party architecture to enable multi-step authorization as well as the instant provisioning of a dynamic security policy in the sensors. Hidra also enables delegated accounting and audit trail. Proposed access control features cope with tightness, feasibility and both dimensions of usability such as scalability and manageability, which are the key unsolved challenges in the foreseen open and dynamic scenarios enabled by IoT. Related to efficiency, the high compression factor of the proposed policy codification and the optimized Hidra security protocol relying on a symmetric cryptographic schema enable the feasibility as it is demonstrated by the validation assessment. Specifically, the security evaluation and both the analytical and experimental performance evaluation demonstrate the feasibility and adequacy of the proposed protocol and access control model.Concretely, the security validation consists of the assessment that the Hidra security protocol meets the security goals of mutual strong authentication, fine-grained authorization, confidentiality and integrity of secret data and accounting. The security analysis of Hidra conveys on the one hand, how the design aspects of the message exchange contribute to the resilience against potential attacks. On the other hand, a formal security validation supported by a software tool named AVISPA ensures the absence of flaws and the correctness of the design of Hidra.The performance validation is based on an analytical performance evaluation and a test-bed implementation of the proposed access control model for the most severely constrained devices. The key performance factor is the length of the policy instance, since it impacts proportionally on the three critical parameters such as the delay, energy consumption, memory footprint and therefore, on the feasibility.Attending to the obtained performance measures, it can be concluded that the proposed policy language keeps such balance since it enables expressive policy instances but always under limited length values. Additionally, the proposed policy codification improves notably the performance of the protocol since it results in the best policy length compression factor compared with currently existing and adopted standards.Therefore, the assessed access control model is the first approach to bring to severely constrained devices a similar expressiveness level for enforcement and accounting as in current Internet. The positive performance evaluation concludes the feasibility and suitability of this access control model, which notably rises the security features on severely constrained devices for the incoming smart scenarios.Additionally, there is no comparable impact assessment of policy expressiveness of any other access control model. That is, the presented analysis models as well as results might be a reference for further analysis and benchmarkingGaur egun darabilzkigun hainbeste gailutan mikroprozesadoreak daude txertatuta, eragiten duten prozesuan neurketak egin eta logika baten ondorioz ekiteko. Horretarako, bai sentsoreak eta baita aktuadoreak erabiltzen dira (hemendik aurrera, komunitatean onartuta dagoenez, sentsoreak esango diegu nahiz eta erabilpen biak izan). Orain arteko erabilpen zabalenetako konekzio motak, banaka edota sare lokaletan konekatuta izan dira. Era honetan, sentsoreak elkarlanean elkarreri eraginez edota zerbitzari nagusi baten agindupean, erakunde baten prozesuak ahalbideratu eta hobetzeko erabili izan dira.Internet of Things (IoT) deritzonak, sentsoreak dituzten gailuak Internet sarearen bidez konektatu eta prozesu zabalagoak eta eraginkorragoak ahalbidetzen ditu. Smartcity, Smartgrid, Smartfactory eta bestelako smart adimendun ekosistemak, gaur egun dauden eta datozen komunikaziorako teknologien aukerak baliatuz, erabilpen berriak ahalbideratu eta eragina areagotzea dute helburu.Era honetan, ekosistema hauek zabalak dira, eremu ezberdinetako erakundeek hartzen dute parte, eta berariazko sentsoreak dituzten gailuen kopurua izugarri handia da. Sentsoreak beraz, berariazkoak, merkeak eta txikiak dira, eta orain arteko lehenengo erabilpen nagusia, magnitude fisikoren bat neurtzea eta neurketa hauek zerbitzari zentralizatu batera bidaltzea izan da. Hau da, inguruan gertatzen direnak neurtu, eta zerbitzari jakin bati neurrien datuak aldiro aldiro edota atari baten baldintzapean igorri. Zerbitzariak logika aplikatu eta sistema osoa adimendun moduan jardungo du. Jokabide honetan, aurretik ezagunak diren entitateen arteko komunikazioen segurtasuna bermatzearen kexka, nahiz eta Internetetik pasatu, hein onargarri batean ebatzita dago gaur egun.Baina adimendun ekosistema aurreratuak sentsoreengandik beste jokabide bat ere aurreikusten dute. Sentsoreek eurekin harremanak izateko moduko zerbitzuak ere eskaintzen dituzte. Erakunde baten prozesuetan, beste jatorri bateko erakundeekin elkarlanean, jokabide honen erabilpen nagusiak bi dira. Batetik, prozesuan parte hartzen duen erabiltzaileak (eta jabeak izan beharrik ez duenak) inguruarekin harremanak izan litzake, eta bere ekintzetan gailuak bere berezitasunetara egokitzearen beharrizana izan litzake. Bestetik, sentsoreen jarduera eta mantenimendua zaintzen duten teknikariek, beroriek egokitzeko zerbitzuen beharrizana izan dezakete.Holako harremanak, sentsoreen eta erabiltzaileen kokalekua zehaztugabea izanik, kasu askotan Internet bidez eta zuzenak (end-to-end) izatea aurreikusten da. Hau da, sentsore txiki asko daude handik hemendik sistemaren adimena ahalbidetuz, eta harreman zuzenetarako zerbitzu ñimiñoak eskainiz. Batetik, zerbitzu zuzena, errazagoa eta eraginkorragoa dena, bestetik erronkak ere baditu. Izan ere, sentsoreak hain txikiak izanik, ezin dituzte gaur egungo protokolo eta mekanismo estandarak gauzatu. Beraz, sare mailatik eta aplikazio mailarainoko berariazko protokoloak sortzen ari dira.Tamalez, protokolo hauek arinak izatea dute helburu eta segurtasuna ez dute behar den moduan aztertu eta gauzatzen. Eta egon badaude berariazko sarbide kontrolerako ereduak baina baliabideen urritasuna dela eta, ez dira ez zorrotzak ez kudeagarriak. Are gehiago, Gartnerren arabera, erabilpen aurreratuetan inbertsioa gaur egun mugatzen duen traba Nagusia segurtasunarekiko mesfidantza da.Eta hauxe da erronka eta tesi honek landu duen gaia: batetik sentsoreak hain txikiak izanik, eta baliabideak hain urriak (10kB RAM, 100 kB Flash eta bateriak, sentsore txikienetarikoetan), eta bestetik Internet sarea hain zabala eta arriskutsua izanik, segurtasuna areagotuko duen sarbide zuzenaren kontrolerako eredu zorrotz, arin eta kudeagarri berri bat zehaztu eta bere erabilgarritasuna aztertu